Oct 8 (Reuters) - AT&T Inc’s WarnerMedia is preparing a restructuring that aims to cut costs by as much as 20% and would result in layoffs, the Wall Street Journal reported on Thursday, citing people familiar with the matter. The overhaul, which is expected to begin in the coming weeks, would result in thousands of layoffs across Warner Bros Studios and TV channels like HBO, TBS and TNT, according to the report here. The company did not immediately respond to a Reuters request for comment. (Reporting by Ayanti Bera in Bengaluru; Editing by Anil D’Silva)